Snapchat is a whole new paradigm in the world of communication: instant, temporary and personal. Sharing photos over Snapchat gives you far more control over your photos than public social sites such as Facebook or Instagram. You and only you get to decide who gets to see your pictures, and they can’t keep them for longer than 10 seconds.

But what happens when you start receiving Snapchat messages from someone you don’t know, or don’t want to hear from? It can be immensely frustrating and soon you might wind up hating the sound of a new Snapchat notification. But don’t worry, help is at hand. Like most social media apps, Snapchat offers an easy feature to block anyone who is annoying you. So how do you block someone on Snapchat?

It’s pretty easy to do. Just follow these steps:

1. Open up the Snapchat app on your mobile device. Blocking is not possible on the Snapchat website, so you’ll need to use the app.

2. Tap the checklist icon on the bottom righthand corner of the Snapchat screen. Pressing this button will bring up your Friends list.

3. Scroll through your list of friends (which might take a while if you’re really popular) and select the person you want to block. Tap on their name to bring up the relevant context menu.

4. You’ll now have three options. On both iOS and Android, the third option is “Block“. Hit this to make the block effective.

5. Go back to your Friends list and you’ll now see the offending person has a big red BLOCKED icon above their name.

So you’ve blocked them, now what happens? The unlucky Snapchatter will no longer be able to send you messages, you will not appear in their friends list, and they cannot search for you by name. To them, it will look like you have stopped using the service altogether. In fact, this might be useful if you don’t want to tell the other person that you’ve blocked them: just say that you’ve deleted your account. They’ll never know the difference.

You’ll still see their name in your friends list and you can choose to unblock them at any time. Simply follow the exact steps as listed above, but this time you’ll see an Unblock button. Once you’ve unblocked a user, you’ll be visible to them again but you’ll need to add each other as friends again before you can start sharing photos.

Wise use of the Snapchat block function is an important part of having a safe and fun Snapchat experience, so it’s important that everyone knows the answer to the question “How do you block someone on Snapchat?” The problem with such a private service can sometimes be that it’s easier to bully or harass people. In some cases, it may be worth reporting this back to Snapchat or, in extreme cases, the local law enforcement authorities. But for the majority of cases, a simple block will allow you to carry on having a great time in Snapchat without that one really annoying person bugging you.